Ceiling insulation Question

[aglad]

This is a flat roof with no attic and no venting. The only space between the roof deck and the ceiling is the width of the rafters. What is the proper way of insulating this ceiling.

[Troy Farmer]

Fibergalss Batts (rolled batts)

[mreusch]

You could have it spray foamed possibly.

[Brian E. Kelly]

Either batts or spray. If fiberglass batts are used no vapor barrier, as the paper vapor barrier is not supposed to be left exposed in the attic.

[jkogel]

Anthony, you should ask some local builders, as to the question of vapour barrier and venting. I believe outdoor humidity is higher in Florida and there are unique rules there. In my cold wet climate, a tightly sealed vapour barrier on the warm interior cieling is a must. Wouldn't build anythng with a flat roof, either.

John Kogel
www.allsafehome.ca

[Brian E. Kelly]

Originally Posted by aglad

This is a flat roof with no attic and no venting. The only space between the roof deck and the ceiling is the width of the rafters. What is the proper way of insulating this ceiling.

Is the flat roof foam on top?

No vapor barrier was not the right answer.

This vapor retarder is flammable
and should not be left exposed.”

This warning is also printed on
most packaging and product literature.
For those applications where the
vapor retarder facing is left exposed,
such as garage walls or ceilings of
warehouses and other storage areas,
flame spread-resistant (FS-25) faced
fiber glass insulation is available.

http://www.naima.org/pages/resources/library/pdf/BI472.PDF

[klott]

Hard to tell, but those look like 2"x6" over a pretty long span also, especially on a flat roof.